Process of dyeing.



NITED STATES PATENT OFFICE.-

AUGUST SIEGMUND, OF LUDWIGSHAFEN, GERMANY, ASSIGNOR TO THE BADISOHE ANILIN AND SODA 'FABRIK, OF SAME PLACE.

PROCESS OF DYEING.

SPECIFICATION forming part of Letters Patent No. 659,556, dated October 9, 1900.

Application filed July 24, 1900- Serial No. 24,71Z- (No specimens.)

T0 aZZ whom it may concern.-

Be it known that I, AUGUST SIEGMUND, dyer, a subject of the King of Prussia, German Emperor, residing at Ludwigshafen-onthe-Rhine, in the Kingdom of Bavaria and Empire of Germany, have invented new and useful Improvements in Processes of Dyeing Wool, of which the followingis aspecification.

In the art of wool-dyeing it is often very desirable to combine perfect level dyeing with the highest possible clearness and brilliancy of shade attainable, especially Where delicate shades are demanded. This is particularly true in the case of Zephyr yarns. It has long been known that no matter how carefully the wool has been bleached prior to dyeing the shade obtained is always more or less sad. This sad appearance can be removed only by the old and well-known operation of stovingthat is, by subjecting the dyed and whizzed goods, whether loose, spun, or woven, to a treatment with sulfur dioxid in the sulfurcham her. The stoving operation is absolutely essential for certain dyestuffs when used where the highest possible brilliancy is required, and without such treatment many dyestuffs would be inapplicable to this branch of the art of dyeingfor example, rhodamiu, auramin, &c. It is obvious that only such dyestuffs are available for this purpose as are fast against sulfur dioxid and which are consequently known in the art as being fast to stoving. It is also ovbious that this stoving operation increases the time necessary for the dyeing of a certain quantity of material and also adds to the cost of manufacture of the dyed goods. Moreover, this old process is attended with an expenditure of a very great amount of care, brought about by the difficulties it causes in dyeing to shade, inasmuch as it frequently causes a change in shade or a lightening or both, which is exceedingly troublesome and irksome to rectify and so causes an extra expenditure of labor and dyestuff. The rectification of such a shade is an operation not generally attended with success.

The object of this invention is to obviate this additional and irksome operation of stoving and the attendant labor of bringing the stoved goods to shade, and thus to simplify and to reduce the cost of the process of obtaining these highly-desirable level and clear shades.

This invention is based upon the new and striking observation that all the advantages which dyed goods show after having been subjected to stoving are obtained by adding to the dye-bath simultaneously with the dyestuif and chemicals sulfurous acid or such substances as will develop sulfurous acid under the conditions prevailing in the dye-bath, dyeing, and finishing, as usual, without stoving. It has also been observed that there is a decided gain in clearness of shade as well as also a saving in the amount of dyestuff required to produce a certain shade as against the old process. In addition to this there is also in many cases the great advantage that the dyer can dye to shade directly and without running the risk of being obliged to sub mit the stoved goods to a subsequent and troublesome treatment with dyestufi in order to get to shade. These effects and advantages are not to be obtained by subjecting the dyed goods to a bath of sulfurous acid,whether the sulfurous acid be added to the dye-bath after it has been exhausted or whether the dyed goods are treated in the well-known way in a separate bath containing sulfurous acid, for in that case a lightening of the shade without any increase in brilliancy resultsthat is, the dyestuff is stripped from off the fiber.

In the following an example is given as to how this invention can be applied. For one hundred pounds of goods prepare a dye-bath as follows: three hundred and seventy-five (375) gallons of water, five (5') pounds of bisulfite of soda of 38 Baum, three and a quarter (3%) ounces of rhodamin 38, ten (10) pounds of Glauber salts, and two (2) pounds of sulfuric acid of 66 Baum; enter, bring to boil, and dye to shade.

In place of the rhodamin in the preceding example any of the other dyestuffs which are fast to stoving may be used. Among these may be particularly mentioned auramin, methyl violet, victoria blue, palatin scarlet, fast yellow, acid violet 4R, alkali violet, victoria night-blue, &c.

What I claim is- 1. The process of dyeing wool, which con- In testimony whereof I have hereunto set s'is'ts in dyeing thematerial in a bath eontain- H my hand in the presence of two subscribing ing a. dyestuffi whi ch is fast to stoving and sulfurous acid, all Substantially as described. witnesses.

2. The process of dyeing wool, which con- AUGUST SIEGMUND. 5 sists indyeing the materialin a. bath contain- Witnesses:

BERNHARD C. HESSE,

ing rhodamin and sulfurous acid, all substantially as described.

JACOB ADRIAN. 

